340 lines
9.6 KiB
C
340 lines
9.6 KiB
C
#include "inc.h"
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#include <minix/vfsif.h>
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PRIVATE int dummyproc;
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FORWARD _PROTOTYPE( int safe_io_conversion, (endpoint_t, cp_grant_id_t *,
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int *, cp_grant_id_t *, int,
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endpoint_t *, void **, int *,
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vir_bytes));
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FORWARD _PROTOTYPE( void safe_io_cleanup, (cp_grant_id_t, cp_grant_id_t *,
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int));
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FORWARD _PROTOTYPE( int gen_opcl, (endpoint_t driver_e, int op,
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dev_t dev, int proc_e, int flags));
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FORWARD _PROTOTYPE( int gen_io, (endpoint_t task_nr, message *mess_ptr));
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/*===========================================================================*
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* fs_new_driver *
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*===========================================================================*/
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PUBLIC int fs_new_driver(void)
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{
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/* New driver endpoint for this device */
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driver_endpoints[(fs_m_in.REQ_DEV >> MAJOR) & BYTE].driver_e =
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fs_m_in.REQ_DRIVER_E;
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return(OK);
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}
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/*===========================================================================*
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* safe_io_conversion *
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*===========================================================================*/
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PRIVATE int safe_io_conversion(driver, gid, op, gids, gids_size,
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io_ept, buf, vec_grants, bytes)
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endpoint_t driver;
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cp_grant_id_t *gid;
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int *op;
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cp_grant_id_t *gids;
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int gids_size;
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endpoint_t *io_ept;
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void **buf;
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int *vec_grants;
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vir_bytes bytes;
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{
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int j;
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iovec_t *v;
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static iovec_t new_iovec[NR_IOREQS];
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/* Number of grants allocated in vector I/O. */
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*vec_grants = 0;
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/* Driver can handle it - change request to a safe one. */
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*gid = GRANT_INVALID;
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switch(*op) {
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case MFS_DEV_READ:
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case MFS_DEV_WRITE:
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/* Change to safe op. */
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*op = *op == MFS_DEV_READ ? DEV_READ_S : DEV_WRITE_S;
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if((*gid=cpf_grant_direct(driver, (vir_bytes) *buf,
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bytes, *op == DEV_READ_S ? CPF_WRITE :
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CPF_READ)) < 0) {
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panic("cpf_grant_magic of buffer failed");
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}
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break;
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case MFS_DEV_GATHER:
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case MFS_DEV_SCATTER:
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/* Change to safe op. */
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*op = *op == MFS_DEV_GATHER ?
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DEV_GATHER_S : DEV_SCATTER_S;
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/* Grant access to my new i/o vector. */
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if((*gid = cpf_grant_direct(driver,
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(vir_bytes) new_iovec, bytes * sizeof(iovec_t),
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CPF_READ | CPF_WRITE)) < 0) {
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panic("cpf_grant_direct of vector failed");
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}
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v = (iovec_t *) *buf;
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/* Grant access to i/o buffers. */
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for(j = 0; j < bytes; j++) {
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if(j >= NR_IOREQS)
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panic("vec too big: %d", bytes);
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new_iovec[j].iov_addr = gids[j] =
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cpf_grant_direct(driver, (vir_bytes)
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v[j].iov_addr, v[j].iov_size,
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*op == DEV_GATHER_S ? CPF_WRITE : CPF_READ);
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if(!GRANT_VALID(gids[j])) {
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panic("mfs: grant to iovec buf failed");
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}
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new_iovec[j].iov_size = v[j].iov_size;
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(*vec_grants)++;
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}
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/* Set user's vector to the new one. */
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*buf = new_iovec;
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break;
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}
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/* If we have converted to a safe operation, I/O
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* endpoint becomes FS if it wasn't already.
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*/
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if(GRANT_VALID(*gid)) {
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*io_ept = SELF_E;
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return 1;
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}
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/* Not converted to a safe operation (because there is no
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* copying involved in this operation).
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*/
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return 0;
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}
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/*===========================================================================*
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* safe_io_cleanup *
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*===========================================================================*/
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PRIVATE void safe_io_cleanup(gid, gids, gids_size)
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cp_grant_id_t gid;
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cp_grant_id_t *gids;
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int gids_size;
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{
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/* Free resources (specifically, grants) allocated by safe_io_conversion(). */
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int j;
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cpf_revoke(gid);
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for(j = 0; j < gids_size; j++)
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cpf_revoke(gids[j]);
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return;
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}
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/*===========================================================================*
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* dev_open *
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*===========================================================================*/
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PUBLIC int dev_open(
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endpoint_t driver_e,
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dev_t dev, /* device to open */
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int proc, /* process to open for */
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int flags /* mode bits and flags */
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)
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{
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int major, r;
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/* Determine the major device number call the device class specific
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* open/close routine. (This is the only routine that must check the
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* device number for being in range. All others can trust this check.)
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*/
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major = (dev >> MAJOR) & BYTE;
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if (major >= NR_DEVICES) major = 0;
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r = gen_opcl(driver_e, DEV_OPEN, dev, proc, flags);
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if (r == SUSPEND) panic("suspend on open from");
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return(r);
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}
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/*===========================================================================*
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* block_dev_io *
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*===========================================================================*/
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PUBLIC int block_dev_io(
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int op, /* MFS_DEV_READ, MFS_DEV_WRITE, etc. */
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dev_t dev, /* major-minor device number */
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int proc_e, /* in whose address space is buf? */
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void *buf, /* virtual address of the buffer */
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u64_t pos, /* byte position */
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int bytes, /* how many bytes to transfer */
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int flags /* special flags, like O_NONBLOCK */
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)
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{
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/* Read or write from a device. The parameter 'dev' tells which one. */
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int r, safe;
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message m;
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cp_grant_id_t gid = GRANT_INVALID;
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int vec_grants;
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int op_used;
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void *buf_used;
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static cp_grant_id_t gids[NR_IOREQS];
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endpoint_t driver_e;
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/* Determine driver endpoint for this device */
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driver_e = driver_endpoints[(dev >> MAJOR) & BYTE].driver_e;
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/* See if driver is roughly valid. */
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if (driver_e == NONE) return(EDEADEPT);
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/* The io vector copying relies on this I/O being for FS itself. */
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if(proc_e != SELF_E) {
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printf("ISOFS(%d) doing block_dev_io for non-self %d\n", SELF_E, proc_e);
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panic("doing block_dev_io for non-self: %d", proc_e);
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}
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/* By default, these are right. */
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m.IO_ENDPT = proc_e;
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m.ADDRESS = buf;
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buf_used = buf;
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/* Convert parameters to 'safe mode'. */
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op_used = op;
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safe = safe_io_conversion(driver_e, &gid,
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&op_used, gids, NR_IOREQS, &m.IO_ENDPT, &buf_used,
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&vec_grants, bytes);
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/* Set up rest of the message. */
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if (safe) m.IO_GRANT = (char *) gid;
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m.m_type = op_used;
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m.DEVICE = (dev >> MINOR) & BYTE;
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m.POSITION = ex64lo(pos);
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m.COUNT = bytes;
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m.HIGHPOS = ex64hi(pos);
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/* Call the task. */
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r = sendrec(driver_e, &m);
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if(r == OK && m.REP_STATUS == ERESTART) r = EDEADEPT;
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/* As block I/O never SUSPENDs, safe cleanup must be done whether
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* the I/O succeeded or not. */
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if (safe) safe_io_cleanup(gid, gids, vec_grants);
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/* RECOVERY:
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* - send back dead driver number
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* - VFS unmaps it, waits for new driver
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* - VFS sends the new driver endp for the FS proc and the request again
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*/
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if (r != OK) {
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if (r == EDEADSRCDST || r == EDEADEPT) {
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printf("ISOFS(%d) dead driver %d\n", SELF_E, driver_e);
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driver_endpoints[(dev >> MAJOR) & BYTE].driver_e = NONE;
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return(r);
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}
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else if (r == ELOCKED) {
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return(r);
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}
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else
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panic("call_task: can't send/receive: %d", r);
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} else {
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/* Did the process we did the sendrec() for get a result? */
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if (m.REP_ENDPT != proc_e) {
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printf("ISOFS (%d) strange device reply from %d, type = %d, proc = %d (not %d) (2) ignored\n", SELF_E, m.m_source, m.m_type, proc_e, m.REP_ENDPT);
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r = EIO;
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}
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}
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/* Task has completed. See if call completed. */
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if (m.REP_STATUS == SUSPEND) {
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panic("ISOFS block_dev_io: driver returned SUSPEND");
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}
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if(buf != buf_used && r == OK) {
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memcpy(buf, buf_used, bytes * sizeof(iovec_t));
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}
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return(m.REP_STATUS);
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}
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/*===========================================================================*
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* gen_opcl *
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*===========================================================================*/
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PRIVATE int gen_opcl(
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endpoint_t driver_e,
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int op, /* operation, DEV_OPEN or DEV_CLOSE */
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dev_t dev, /* device to open or close */
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int proc_e, /* process to open/close for */
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int flags /* mode bits and flags */
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)
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{
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/* Called from the dmap struct in table.c on opens & closes of special files.*/
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message dev_mess;
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dev_mess.m_type = op;
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dev_mess.DEVICE = (dev >> MINOR) & BYTE;
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dev_mess.IO_ENDPT = proc_e;
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dev_mess.COUNT = flags;
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/* Call the task. */
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gen_io(driver_e, &dev_mess);
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return(dev_mess.REP_STATUS);
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}
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/*===========================================================================*
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* gen_io *
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*===========================================================================*/
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PRIVATE int gen_io(task_nr, mess_ptr)
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endpoint_t task_nr; /* which task to call */
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message *mess_ptr; /* pointer to message for task */
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{
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/* All file system I/O ultimately comes down to I/O on major/minor device
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* pairs. These lead to calls on the following routines via the dmap table.
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*/
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int r, proc_e;
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proc_e = mess_ptr->IO_ENDPT;
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r = sendrec(task_nr, mess_ptr);
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if(r == OK && mess_ptr->REP_STATUS == ERESTART) r = EDEADEPT;
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if (r != OK) {
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if (r == EDEADSRCDST || r == EDEADEPT) {
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printf("fs: dead driver %d\n", task_nr);
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panic("should handle crashed drivers");
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/* dmap_unmap_by_endpt(task_nr); */
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return r;
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}
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if (r == ELOCKED) {
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printf("fs: ELOCKED talking to %d\n", task_nr);
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return r;
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}
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panic("call_task: can't send/receive: %d", r);
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}
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/* Did the process we did the sendrec() for get a result? */
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if (mess_ptr->REP_ENDPT != proc_e) {
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printf(
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"fs: strange device reply from %d, type = %d, proc = %d (not %d) (2) ignored\n",
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mess_ptr->m_source,
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mess_ptr->m_type,
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proc_e,
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mess_ptr->REP_ENDPT);
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return(EIO);
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}
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return(OK);
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}
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/*===========================================================================*
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* dev_close *
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*===========================================================================*/
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PUBLIC void dev_close(endpoint_t driver_e, dev_t dev)
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{
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(void) gen_opcl(driver_e, DEV_CLOSE, dev, 0, 0);
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}
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